A speaker vibrates when outputting a sound. Therefore, in terms of improving a sound quality and suppressing the vibrations to peripheral portions thereto, a variety of measures are taken for preventing the vibrations from being transferred in a way that takes into consideration how the vibrations are transferred from the speaker to peripheral structures thereto. Further, it is desirable for a user to adjust a position and a direction of the speaker in an unrestricted manner in order to form a favorite acoustic space.
Under such circumstances, for example, as disclosed in Patent document 1, a technology is proposed, in which support pins each taking a cone shape are supported on footpads on a point-contact basis, and an anti-vibration sleeve is used for covering these pins; and as disclosed in Patent document 2, a technology is proposed, which prevents a decline of acoustic performance by supporting the speaker on one single support rod. A technology other than these technologies is proposed, which enables, as disclosed in, e.g., Patent document 3, a plurality of stacked speakers to be joined easily.                [Patent document 1] Japanese Registered Utility Model Application Publication No. 3107462        [Patent document 2] Japanese Patent Application Laid-Open Publication No. H11-289588        [Patent document 3] Japanese Unexamined Utility Model Application Publication No. H05-6993        